Error 443 — Operation prohibited due to the pressure drop

What does 443 mean?

The system's operation is prohibited because a significant pressure drop has been detected. This is a safety measure to prevent damage to components like the compressor due to insufficient refrigerant flow or charge.

• Severe refrigerant leakage
• Major blockage in the refrigerant lines (e.g., kinked pipe, clogged filter)
• Faulty pressure sensor
• Compressor malfunction affecting pressure

Click steps to track your progress.

1. 1

   Turn off the outdoor unit immediately to prevent further damage.

2. 2

   Look for any signs of major refrigerant leakage, such as large areas of frost or oil stains.

3. 3

   Listen for unusual sounds (hissing, gurgling) from the refrigerant lines.

4. 4

   This error almost always requires a professional HVAC technician to diagnose the source of the pressure drop.

5. 5

   Do not attempt to restart the unit until a professional has inspected and repaired the system.